Static pressure packer capable of being backwashed

Abstract

The utility model relates to the technical field of oil development downhole tools, and discloses a backflushing static pressure packer which comprises a central pipe, the upper end of the central pipe is in threaded connection with an upper end head, the lower end of the central pipe is in threaded connection with a lower end head, a hydraulic anchor and a backflushing mechanism are sleeved on the central pipe, and the inside of the hydraulic anchor is sealed with the outer circle of the upper end of the central pipe through an O-shaped ring. The backwashing mechanism comprises a valve body arranged on the central pipe in a sleeving mode and a valve sleeve arranged on the valve body in a sleeving mode, the valve sleeve is connected with the hydraulic anchor, and a backwashing spring is arranged between the valve body and the hydraulic anchor. According to the iron static pressure packer capable of being backwashed, the pressure grade of ground equipment can be greatly reduced, meanwhile, the function of backwashing a well is provided, and the well washing requirement of a pipe column is met.

Description

Technical Field

[0001] The utility model relates to the technical field of downhole tools for petroleum development, in particular to a static pressure packer capable of backwashing. Background Art

[0002] At present, in the production, water (gas) injection and interlayer isolation process of highly deviated wells and horizontal wells, the surface equipment and tubing cannot provide high hydraulic pressure due to the limitation of service life. In addition, considering the particularity of the wellbore structure and trajectory of highly deviated wells and horizontal wells, the rotation and application of tubing weight cannot be used to set the packer; therefore, the existing packers set by lifting and lowering the tubing, rotating the tubing, tubing hydraulics, self-sealing, and lowering tools are difficult to set in highly deviated wells and horizontal formation tests, so only hydrostatic set packers can meet this special demand. At the same time, some well conditions need to add a backwashing function to meet the well washing needs, but there is currently no hydrostatic set packer that can backwash on the market. Summary of the invention

[0003] The purpose of the utility model is to provide a backwashable static pressure packer to address the deficiencies of the above-mentioned technology, which can significantly reduce the pressure level of ground equipment and provide a backwashing well function to meet the pipe string well washing needs.

[0004] To achieve the above-mentioned purpose, the utility model is provided with a backwashable static pressure packer, comprising a center tube, wherein the upper end of the center tube is threadedly connected to an upper end head, and the lower end is threadedly connected to a lower end head, a hydraulic anchor and a backwash mechanism are sleeved on the center tube, the interior of the hydraulic anchor is sealed with the outer circle of the upper end of the center tube by an O-ring, when the packer is sealed, the hydraulic anchor can move on the center tube together with the rubber tube, and at the same time, when the packer is lifted to unseal, the center tube can balance the upper and lower pressure differences after the sealing section of the hydraulic anchor is separated, which makes it easier to unseal the packer, and the backwash mechanism comprises a valve body sleeved on the center tube and a valve sleeve sleeved on the valve body, the valve sleeve is connected to the hydraulic anchor, a backwash spring is arranged between the valve body and the hydraulic anchor, which is pressed by the upper pressure difference, and the backwash channel can be opened once the pressure difference overcomes the spring force and the friction force of the O-ring.

[0005] Preferably, the hydraulic anchor includes a hydraulic anchor seat sleeved on the central pipe, the hydraulic anchor seat is provided with a ball tooth, the ball tooth is provided with a plurality of spring guide nails, the spring guide nails are sleeved with a ball tooth spring, the hydraulic anchor seat is covered with a pressing plate, the valve sleeve is threadedly connected to the hydraulic anchor seat, and the ball tooth of the hydraulic anchor will extend out of the hydraulic anchor seat and be anchored on the casing under the action of the pressure difference under the pipe column, thereby preventing the pipe column from moving up, and at the same time, the spring guide nails can fix the ball tooth spring in the radial direction of the hydraulic anchor seat, thereby preventing the ball tooth spring from being unable to return to the original position due to compression and bending deformation.

[0006] Preferably, a supporting sleeve is sleeved on the central tube, one end of the supporting sleeve is threadedly connected to the valve sleeve, and a rubber cylinder is also sleeved on the supporting sleeve, the rubber cylinder includes an upper rubber cylinder, a lower rubber cylinder and an intermediate rubber cylinder located between the upper rubber cylinder and the lower rubber cylinder, and spacer rings are provided between the upper rubber cylinder and the intermediate rubber cylinder and between the lower rubber cylinder and the intermediate rubber cylinder, the upper rubber cylinder and the valve sleeve are threadedly connected by an upper guide ring, and the lower rubber cylinder and the vertebral body sleeved on the supporting sleeve are threadedly connected by a lower guide ring.

[0007] Preferably, the lower end of the vertebral body has at least four evenly arranged dovetail grooves, and the middle of the vertebral body is provided with at least two symmetrical screw holes. The vertebral body is restricted to the support sleeve by two screws so that it can only move axially, thereby preventing the vertebral body and the support sleeve from rotating relative to each other. A cava is also sleeved on the bottom of the support sleeve, and the cava includes the same number of cava pieces as the dovetail grooves, each of which consists of 45° right-angle teeth, dovetail wings and tail guide grooves. The cava can both anchor the casing and connect the vertebral body. The dovetail groove design of the vertebral body and the cava can satisfy the need for anchoring the casing of the packer, and the dovetail groove can limit the cava when unsealing to prevent the cava from falling off.

[0008] Preferably, a sealing sleeve is sleeved at the lower part of the center pipe, and the supporting sleeve is connected to the sealing sleeve by a connecting sleeve. The connecting sleeve is provided with three waist-shaped grooves, each of which is equipped with a cam block. The connecting sleeve is also provided with a cam block retaining ring, which is also sleeved on the connecting sleeve. When the cam block retaining ring cuts off the pin and moves upward to make room for the cam block, the supporting sleeve can drive the hydraulic anchor and the rubber cylinder to move downward for sealing. This mechanism can prevent the tool from being sealed midway during the process of entering the well. A starting piston is also sleeved on the connecting sleeve, and the starting piston is connected to the connecting sleeve by a starting pin. Different numbers of shear pins can be set for different well depths, and the sealer has a wider adaptability.

[0009] Preferably, a sealing ring and a sealing ring retaining ring are arranged at the lower part of the center tube, and the center tube, connecting sleeve, sealing sleeve and sealing ring are combined to form an air cavity, and a shock-absorbing pad is provided at the lower end of the air cavity. The air cavity is the key to the static pressure sealing of the entire packer. As the packer is lowered deeper, the liquid column pressure of the tubing and the air cavity form a hydrostatic pressure, which can directly act on the piston to seal the packer.

[0010] Preferably, a release ring is fixedly installed at the lower part of the central pipe through a release ring seat and screws. By lifting the pipe column and cutting the release ring, the slips and the rubber cylinder can be released to complete the unsealing of the packer.

[0011] Preferably, a locking ring is also sleeved on the central pipe, and after the packer is set, the locking ring can be used to tighten the rubber cylinder and the slips to prevent the rubber cylinder from rebounding.

[0012] Compared with the prior art, the utility model has the following advantages:

[0013] 1. Providing the setting force through the static pressure of the oil pipe can greatly reduce the hydraulic pressure provided by the ground equipment;

[0014] 2. Provide backwash channel and provide solutions for pipe string backwash;

[0015] 3. An air cavity is designed in the structure. As the packer is lowered deeper into the well, the hydraulic setting force required becomes smaller.

[0016] 4. It can be used as the lowest packer in a single or multi-stage packer string and lowered into the well. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model is a schematic structural diagram of a backwashable static pressure packer.

[0018] The components in the figure are numbered as follows:

[0019] Center pipe 1, upper end 2, lower end 3, hydraulic anchor 4, backwash mechanism 5, O-ring 6, valve body 7, valve sleeve 8, backwash spring 9, hydraulic anchor seat 10, ball tooth 11, spring guide nail 12, ball tooth spring 13, pressing piece 14, rubber cylinder 15, upper rubber cylinder 16, lower rubber cylinder 17, middle rubber cylinder 18, spacer ring 19, vertebral body 20, lower guide ring 21, upper guide ring 22, seating sleeve 23, connecting sleeve 24, sealing ring 25, air cavity 26, shock absorbing pad 27, release ring seat 28, release ring 29, locking ring 30, slip sheet 31, support sleeve 32, cam block retaining ring 33, cam block 34, sealing ring retaining ring 35. DETAILED DESCRIPTION

[0020] The utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, a backwashable static pressure packer comprises a central tube 1, the upper end of the central tube 1 is threadedly connected with an upper end head 2, the lower end is threadedly connected with a lower end head 3, a hydraulic anchor 4 and a backwash mechanism 5 are sleeved on the central tube 1, the interior of the hydraulic anchor 4 is sealed with the outer circle of the upper end of the central tube 1 by an O-ring 6, the backwash mechanism 5 comprises a valve body 7 sleeved on the central tube 1 and a valve sleeve 8 sleeved on the valve body 7, the valve sleeve 8 is connected with the hydraulic anchor 4, a backwash spring 9 is arranged between the valve body 7 and the hydraulic anchor 4, and the backwash channel can be opened by applying pressure by the upper pressure difference once the pressure difference overcomes the spring force and the friction force of the O-ring.

[0022] Among them, the hydraulic anchor 4 includes a hydraulic anchor seat 10 sleeved on the central pipe 1, a ball tooth 11 is arranged on the hydraulic anchor seat 10, a plurality of spring guide nails 12 are arranged on the ball tooth 11, a ball tooth spring 13 is sleeved on the spring guide nail 12, a pressing plate 14 is covered on the hydraulic anchor seat 10, and the valve sleeve 8 is threadedly connected to the hydraulic anchor seat 10. Under the action of the pressure difference under the pipe column, the ball tooth 11 of the hydraulic anchor 4 will extend out of the hydraulic anchor seat 10 and anchor on the casing, which can prevent the pipe column from moving up. At the same time, the spring guide nail 12 can fix the ball tooth spring 13 in the radial direction of the hydraulic anchor seat 10, which can prevent the ball tooth spring 13 from being unable to return to the original position due to compression and bending deformation.

[0023] In addition, in this embodiment, a support sleeve 32 is sleeved on the central tube 1, one end of the support sleeve 32 is threadedly connected to the valve sleeve 8, and a rubber sleeve 15 is also sleeved on the support sleeve 32. The rubber sleeve 15 includes an upper rubber sleeve 16, a lower rubber sleeve 17, and an intermediate rubber sleeve 18 located between the upper rubber sleeve 16 and the lower rubber sleeve 17. A spacer ring 19 is provided between the upper rubber sleeve 16 and the intermediate rubber sleeve 18, and between the lower rubber sleeve 17 and the intermediate rubber sleeve 18. The upper rubber sleeve 16 and the valve sleeve 8 are connected by an upper guide. The ring 22 is threadedly connected, and the lower end rubber cylinder 17 is threadedly connected to the vertebral body 20 sleeved on the support sleeve 32 through the lower guide ring 21. In this embodiment, the hardness of the middle rubber cylinder 18 is 70-75DURO, the hardness of the upper end rubber cylinder 16 and the lower end rubber cylinder 17 is 90-95DURO, and the upper end rubber cylinder 16 and the lower end rubber cylinder 17 are sleeved on the support sleeve 32 together with the adjustment ring and the spacer ring 19. The adjustment ring can adjust the situation where the gap of the rubber cylinder 15 is too large due to assembly error.

[0024] In this embodiment, there are four evenly arranged dovetail grooves at the lower end of the vertebral body 20, and two symmetrical screw holes are provided in the middle of the vertebral body 20. The vertebral body 20 is restricted to the support sleeve 32 by two screws so that it can only move axially, thereby preventing the vertebral body 20 and the support sleeve 32 from rotating relative to each other. A cava is also provided at the bottom of the support sleeve 32, and the cava includes cava pieces 31 with the same number as the dovetail grooves. Each cava piece 31 consists of 45° right-angle teeth, dovetail wings and tail guide grooves. The cava can both anchor the casing and connect the vertebral body 20. The dovetail groove design of the vertebral body 20 and the cava can satisfy the anchoring casing of the packer, and the dovetail groove can limit the cava when unsealing to prevent the cava from falling off.

[0025] In this embodiment, a sealing sleeve 23 is sleeved on the lower part of the center pipe 1, and the supporting sleeve 32 is connected to the sealing sleeve 23 by a connecting sleeve 24. The connecting sleeve 24 is provided with three waist-shaped grooves arranged at the same place, and a cam block 34 is installed in each waist-shaped groove. A cam block retaining ring 33 is also provided on the connecting sleeve 24. When the cam block retaining ring 33 cuts off the pin and moves upward to make room for the cam block 34, the supporting sleeve 32 can drive the hydraulic anchor 4 and the rubber cylinder 15 to move downward for sealing. This mechanism can prevent the tool from being sealed in the middle of entering the well. A starting piston is also sleeved on the connecting sleeve 24, and the starting piston and the connecting sleeve 24 are connected by a starting pin. Different numbers of shear pins can be set for different well depths, and the packer has a wider adaptability.

[0026] In this embodiment, a sealing ring 25 and a sealing ring retaining ring 35 are sleeved at the lower part of the center pipe 1. The center pipe 1, the connecting sleeve 24, the sealing sleeve 23 and the sealing ring 25 enclose an air cavity 26. A shock-absorbing pad 27 is provided at the lower end of the air cavity 26. The air cavity is the key to the static pressure sealing of the entire packer. As the packer is lowered deeper, the liquid column pressure of the tubing and the air cavity 26 form a hydrostatic pressure, which can directly act on the piston to seal the packer.

[0027] In this embodiment, a release ring 29 is fixedly installed at the lower part of the central pipe 1 through a release ring seat 28 and screws. By lifting the pipe string and cutting the release ring 29, the slips and the rubber cylinder 15 can be released to complete the unsealing of the packer.

[0028] In this embodiment, a locking ring 30 is also sleeved on the central pipe 1. After the packer is set, the locking ring 30 can be used to tighten the rubber sleeve 15 and the slips to prevent the rubber sleeve 15 from rebounding.

[0029] When this embodiment is used, during production, water injection, and interlayer isolation, the packer is lowered into the well through the oil pipe, and the packer is lowered to the predetermined sealing depth and the wellhead is seated. The ball is thrown and pumped to the ball seat of the drop plug, and the pressure is slowly increased to be higher than the annular pressure by about 7MPa. This will cut the shear pin on the cam block retaining ring 33, so that the cam block retaining ring 33 moves upward under pressure to release the cam block 34, and the hydraulic anchor 4 and the valve sleeve 7 can produce relative displacement with the central pipe 1. The static liquid column pressure in the wellbore can make the connecting sleeve 24 move downward and compress the air cavity 26 at the lower end of the packer. This action can make the hydraulic anchor seat 10 move downward in the direction of the slip, set the slip and the rubber cylinder 15, and the locking ring 30 on the central pipe 1 locks the hydraulic anchor seat 10 and the upward movement trend of the valve sleeve 8, so that the packer is completely seated.

[0030] After the packer is set, if the tubing shrinks, the center pipe will move upward until the release ring seat 28 presses against the setting sleeve 23. If the oil pipe is extended, the downward movement trend of the center pipe 1 transmits the force to the hydraulic anchor seat 10, valve sleeve 8, rubber cylinder 15 and cone 20 through the locking ring 30 on the center pipe 1, thereby increasing the setting force of the packer.

[0031] If backwashing is required, the annulus at the upper end of the packer can be pressurized. The pressure acts on the valve body 7, overcoming the spring force of the backwash spring 9 to move upward, thereby opening the valve body 7. The liquid enters the annulus at the lower end of the packer through the annulus between the support sleeve 32 and the center pipe 1, and then returns to the ground through the interior of the center pipe 1.

[0032] By lifting the pipe string, the O-ring 6 on the hydraulic anchor seat 10 is separated from the sealing section of the central pipe 1, the packer is connected from top to bottom, and the ball teeth 11 of the hydraulic anchor 4 retracts the hydraulic anchor seat 10 under the action of the spring force of the ball teeth spring 13. The pipe string is further lifted, and the central pipe 1 moves upward with the release ring seat 28 and the release ring 29. When the release ring seat 28 hits the lower sealing ring retaining ring 49, the central pipe 1 shears the release ring 29, and the pipe string is further lifted, and the rubber cylinder 15 and the slips gradually retract to complete the unsealing of the packer.

[0033] The utility model provides a backwashable static pressure packer with a sealing force provided by the static pressure of the oil pipe, which can greatly reduce the hydraulic pressure provided by the ground equipment; a backwash channel is provided to provide a solution for the backwashing of the pipe string; an air cavity 26 is designed from the structural design, and the deeper the well the packer is lowered, the smaller the hydraulic sealing force that needs to be provided becomes; the utility model can be used as the lowest packer in a single or multi-stage packer string to be lowered into the well.

[0034] It should be noted that the description of the above technical solutions is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solutions set forth herein. On the contrary, providing these descriptions will make the disclosure of the utility model thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solution of the utility model is limited only by the scope of the claims.

[0035] The various aspects disclosed for describing the present specification and claims are merely examples, and therefore, the present specification and claims are not limited to the details shown. In the above description, when the detailed description of the related known functions or configurations is determined to be unnecessary to obscure the focus of the present specification and claims, the detailed description will be omitted.

[0036] Finally, it should be pointed out that the above content is a further detailed description of the utility model in combination with the specific implementation method. It cannot be considered that the specific implementation of the utility model is limited to these descriptions. For ordinary technicians in the technical field to which the utility model belongs, simple replacements made without departing from the concept of the utility model should be regarded as belonging to the protection scope of the utility model. The above embodiments are only more representative examples of the utility model. Obviously, the utility model is not limited to the above embodiments, and there can be many variations. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the utility model should be considered to belong to the protection scope of the utility model.

Claims

1. A backwashable static pressure packer, comprising a central tube (1), wherein the upper end of the central tube (1) is threadedly connected to an upper end cap (2), and the lower end of the central tube (1) is threadedly connected to a lower end cap (3), wherein: A hydraulic anchor (4) and a backwash mechanism (5) are sleeved on the central tube (1); the interior of the hydraulic anchor (4) is sealed with the outer circle of the upper end of the central tube (1) via an O-ring (6); the backwash mechanism (5) comprises a valve body (7) sleeved on the central tube (1) and a valve sleeve (8) sleeved on the valve body (7); the valve sleeve (8) is connected to the hydraulic anchor (4); and a backwash spring (9) is provided between the valve body (7) and the hydraulic anchor (4).

2. The backwashable static pressure packer according to claim 1, characterized in that: The hydraulic anchor (4) comprises a hydraulic anchor seat (10) sleeved on the central pipe (1), the hydraulic anchor seat (10) is provided with a ball tooth (11), the ball tooth (11) is provided with a plurality of spring guide pins (12), the spring guide pins (12) are sleeved with a ball tooth spring (13), the hydraulic anchor seat (10) is covered with a pressing sheet (14), and the valve sleeve (8) is threadedly connected to the hydraulic anchor seat (10).

3. The backwashable static pressure packer according to claim 1, characterized in that: A support sleeve (32) is sleeved on the central tube (1), one end of the support sleeve (32) is threadedly connected to the valve sleeve (8), and a rubber sleeve (15) is also sleeved on the support sleeve (32), the rubber sleeve (15) comprising an upper rubber sleeve (16), a lower rubber sleeve (17) and an intermediate rubber sleeve (18) located between the upper rubber sleeve (16) and the lower rubber sleeve (17), and a spacer ring (19) is provided between the upper rubber sleeve (16) and the intermediate rubber sleeve (18) and between the lower rubber sleeve (17) and the intermediate rubber sleeve (18), the upper rubber sleeve (16) and the valve sleeve (8) are threadedly connected via an upper guide ring (22), and the lower rubber sleeve (17) and the cone (20) sleeved on the support sleeve (32) are threadedly connected via a lower guide ring (21).

4. The backwashable static pressure packer according to claim 3, characterized in that: The lower end of the vertebral body (20) is provided with at least four evenly arranged dovetail grooves, the middle of the vertebral body (20) is provided with at least two symmetrical screw holes, the bottom of the support sleeve (32) is also sleeved with a slip, the slip includes slip pieces (31) with the same number as the dovetail grooves, each of the slip pieces (31) is composed of 45° right-angle teeth, a dovetail wing and a tail guide groove.

5. The backwashable static pressure packer according to claim 4, characterized in that: A seating sleeve (23) is sleeved on the lower part of the center tube (1); the support sleeve (32) is connected to the seating sleeve (23) via a connecting sleeve (24); the connecting sleeve (24) is provided with three waist-shaped grooves arranged at the same positions; each waist-shaped groove is provided with a cam block (34); the connecting sleeve (24) is also provided with a cam block retaining ring (33); the connecting sleeve (24) is also sleeved with a starting piston; the starting piston and the connecting sleeve (24) are connected via a starting pin.

6. The backwashable static pressure packer according to claim 5, characterized in that: A sealing ring (25) and a sealing ring retaining ring (35) are sleeved at the lower part of the central tube (1); the central tube (1), the connecting sleeve (24), the setting sleeve (23) and the sealing ring (25) are enclosed to form an air cavity (26); a shock absorbing pad (27) is provided at the lower end of the air cavity (26).

7. The backwashable static pressure packer according to claim 1, characterized in that: A release ring (29) is fixedly mounted on the lower part of the central tube (1) via a release ring seat (28) and screws.

8. The backwashable static pressure packer according to claim 1, characterized in that: A locking ring (30) is also sleeved on the central tube (1).

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